Electrical apparatus



J. W. PATCH.

ELECTRICAL APPARATUS. APPLICATLON man JAN- 15. 1921.

Patented Nova 28, 1922.

Inventor James W.Patch,' y v/aw M H i s Attorney.

Patented Nov. 28, 1922.

STATES PATENT @FFIQE.

JAMES W. PATCH, OF FORT WAYNE INDIANA, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRICAL APPARATUS.

Application filed January 15, 1921.

T 0 all whom it may concern:

' Be it known that 1, JAMES W. PATCH, a citizen of the United States, residing at Fort Wayne, in the county of Allen, State of In diana, have invented certain new and useful Improvements in Electrical Apparatus, of which the following is a specification.

My invention relates to electrical apparatus and particularly to apparatus having windings supported about the legs of magnetic cores, such as are employed in transformers, reactances and the like.

The object of my invention is to provide an improved means for retaining the windings in a predetermined spaced relation with respect to the core which is reliable, safe and readily manufactured.

lVhen assembling windings about the leg of a magnetic core, in the manufacture of electrical apparatus, it is necessary that certain predetermined spaced relations shall be maintained both between the winding groups and between the windings and the core; hence, to secure this end, spacing devices having elements placed in both radial and axial directions are relied upon for maintaining the windings in the desired relations.

To secure the desired spaced relation with respect to the core, it has heretofore been customary to surround the winding leg with an insulating cylinder and slip the windings down over this cylinder, retaining the same in spaced relation with respect thereto by means of spacing strips laid along the cylinder parallel to its geometrical elements.

In the practice of my invention, the use of insulating cylinders, which are themselves expensive to manufacture are dispensed with, since I make use of insulating cylindrical segments fitted about the core, which segments may be manufactured more cheaply than complete cylinders. Further advantage is taken of the configuration had by fitting these cylindrical segments about the windin leg to support the windings on these segments without the aid of insulating strips laid therealong, thus again effecting a saving both in the cost of manufacture and in that of the material employed.

For a more complete understanding of the nature and objects of my invention, reference should be had to the following detailed description taken in connection with the accompanying drawing in which:

Serial No. 437,620.

Figure 1 shows a transformer in side elevation, partly assembled and with parts hrolieaaway, which embodies my invention. Fig. 2 1s a top plan View of the transformer shown in Fig. 1, while Fig. 3 shows in perspective a cylindrical segment such as I employ in the practice of my invention, a portion being broken away.

Referring now to the drawing, 10 denotes a three-legged core having windings 11 assembled about its central leg 12. The core is shown with the top end-iron removed, also a portion of the windings. The windings 11 are here shown as composed of interleaved disc-coils spaced apart by means of radial spacing devices 13 which are preferably disposed at equally s aced intervals on the faces of the coils. r ny other type of windings may, however, be used.

In order to space and insulate the windings from the winding leg 12, I employ insulating cylindrical segments 15 such as are shown in perspe -tive in Fig. 3. These cyinnit-real segnie may he made of any suitable insulating material. I have found, however, that sheets of aper held together by means of a resinous Einder such as shellac, formed under the influence of heat and pressure, yield segments possessing both the desired mechanical and electrical characteristics.

in the form of my invention shown in Fig. four such segments are illustrated as beii disposed about the four corners of the central le the corners thereof having astep ed ilormation whereby its periphery is made 'iore nearly to approach a circle, thus permitting the segments 15 to fit snugly about this central leg. which is the winding leg.

The cylindrical segments 15 are preferably formed to have a radius of curvature such that when disposed in place their veredgos "6 will rest against the sides of the core n 12, while the central portions hear agr iinst the edges of he stepped formation on the leg; the space between two ad jacent edges of the insulating segments being preferably proportioned to he very small.

The coils comprising the windings 11 are made on circular forms and are of such a d' meter as to span a diagonal of the winding leg 12 and the thickness of two insulating cylindr 1 segments when in place. Such a diagonal is shown at a in Fig. 2.

The windings when assembled and put in place about the winding leg thus engage tangentially with the central portions of the cylindrical segments 15 which embrace the leg, and are thus rigidly held in place and spaced from the core. i is thus seen thatwintilating,- spaces are provided between the windings and the cylindrical. segi ents adjacent the edge portions of the cylindrical s' gmeiits. The lfYllllClIlCEtl segments are riade of sufiicient thickness to have dielectric strength enough to resist puncture at the points where they support the windings. i i 0 since the windings are cylindrical in form they are suftlciently spaced away from the core at those points which are opposite the spaces between the edges of the cylindrical insulating segments so that the insulating medium surrounding the windings provides the desired insulation to prevent arcing to ground at these points. The distance from the points where the windings engage with the insulating" segments 15 to their edges resents the creepage distance, which, in this construction, is is necessary to insulate against. For the arrangement shown, this distance is sui'licient'l or insulat- 111. against all ordinary distribution voltraving now described what is at present the best means known to me for ca Tying out an embodiment of my invention, 1 would have it understood that such means are merely illustrative, and that l do not mean to be limited thereby to the e act details shown restricted in the choice oi recognized equivalents except as defined in my claims hereunto annexed.

l i hat l claim as new and desire to secure by Letters Patent of the United. States, is

1. ln an electrical apparatus, the combination with magnetic core having a winding leg, of windings disposed in spaced relation to said leg, and a plurality of insulating; segments inserted between the windings and the winding leg, said segments being of difi'erent curvature from that of the inner face of the windings to provide'ventilating spaces between the segments and windings and between the segments and the winding leg.

2. In an electrical apparatus, the combination with a magnetic core having a winding leg, of windings disposed in spaced relation to said leg, and a plurality oi cylindrical insulating segments inserted between the windings. and the corners of the winding leg, said segments being of greater curvature than that of the inner face of the windto provide ventilating spaces between the segments and winnings and between the segments and the winding leg.

8. in an electrical apparatus, the combination with a magnetic core having a winding leg, of windings disposed in spaced relation to said leg, and. a-plurality of cylindrical insulating segments inserted between the windings and the corners of the winding leg, saidsegments having a radius of curve ture so proportioned that their central portic-ns engage with the corners of said leg and their edges engage withthe sides of said leg, whereby "ventilating spaces are provided between the segments and windings and between the segments and the winding leg.

l. in an electrical apparatus, the combination with a magnetic core having winding leg, of windings disposed in spaced relation to said leg, and a plurality of cylindriial insulating; segments inserted between the windings: and the corners of the wine leg, said segments having a radius ct curvature such that their central portions en with the leg corners and their edges with the sides of said leg, the adjacent ed 'es of diil'erent segments being arranged relatively close together.

In witness whereof, I have hereunto set my hand this 12th day oi J an. 1921.

JAMES W. PATCH. 

